This extremely varied and demanding trail brings you through forests, mountain pastures, rock fields and along alpine footpaths. With its positive as well as negative variation in altitude of over 3'500 m for a total distance of 70 km, this itinerary is reserved for the more advanced trail runner. Your efforts are rewarded by the breathtaking landscapes like the Crêtes de Thyon (mountain ridges), the Grand Désert lake without mentioning the Pra Fleuri pass located at 2987 m in altitude.